Wiktionary
prelight
vb. (context transitive English) To illuminate in advance (context used especially in the rendering of three-dimensional computer graphics English).
Usage examples of "prelight".
Two silken tents, barely visible in the prelight, stood at the edge of the clearing, flags fluttering from their pointed tops.
The torches are doubtless prelighted as a safety precaution and then everyone participating surely advances in a slow-moving line as the torches are handed out.